Charged particle beam device

Abstract

The charged particle beam device of this invention separately detects secondary signal particles emitted from the surface of a sample, dark field signal particles scattered within and transmitted through the sample, bright field signal particles transmitted through the sample without being scattered within the sample, and thereby allows the operator to observe the image with an optimum contrast according to applications. In order to detect only the dark field transmitted signal particles scattered within the sample, among the transmitted signal particles obtained by the primary charged particle beams having transmitted through the thin film sample, the device includes a transmitted signal conversion member having an opening through which the bright field transmitted signal particles not being scattered within the sample can pass, and a detection means for detecting signals colliding against the conversion member.

1. A charged particle beam device, having a source of charged particles for emitting a charged particle beam and a sample stage for placing a sample under the charged particle beam, the charged particle beam device further comprising:
 an object lens for generating a magnetic field to focus the charged particle beam toward the sample; 
 a transmitted signal conversion member for emitting secondary charged particles by collisions of charged particles transmitted through the sample; and 
 a charged particle detector for detecting the secondary charged particles emitted from the transmitted signal conversion member; 
 wherein the object lens generates the magnetic field under the object lens so that the magnetic field prevents charged particles emitted from the sample surface from reaching the charged particle detector, 
 wherein the transmitted signal conversion member is positioned on the path of the charged particles passing through the sample, and for converting the charged particles passing through the sample into secondary charged particles, and 
 wherein the transmitted signal conversion member has an opening through which the charged particles passing through the sample pass, and the opening has an electrode to which a positive voltage is applied. 
 
   
   
     2. A charged particle beam device having a source of charged particles for emitting a charged particle beam and a sample stage for placing a sample under the charged particle beam, the charged particle beam device further comprising:
 an object lens for generating a magnetic field to focus the charged particle beam toward the sample; 
 a transmitted signal conversion member for emitting secondary charged particles by collisions of charged particles transmitted through the sample; and 
 a charged particle detector for detecting the secondary charged particles emitted from the transmitted signal conversion member; 
 wherein the object lens generates the magnetic field under the object lens so that the magnetic field prevents charged particles emitted from the sample surface from reaching the charged particle detector, 
 wherein the transmitted signal conversion member is positioned on the path of the charged particles passing through the sample, and for converting the charged particles passing through the sample into secondary charged particles, and 
 wherein the transmitted signal conversion member has two electrodes having two layers so that the two electrodes emit the secondary charged particles by collisions of the charged particles passing through the sample pass between said two electrodes.